Sharon Strudwick showed no emotion in the dock as she was sentenced in Tamworth District Court on Friday morning in front of dozens of people including the family and colleagues of slain police officer Senior Constable David Rixon.

Strudwick is the former girlfriend of convicted murderer Michael Jacobs - the man jailed for life for the murder of the Tamworth highway patrol police officer in a Tamworth street in March 2012.

Judge Colin Charteris said he had no alternative but to jail Strudwick after she pleaded guilty to acting with intent, namely disposing of .38 calibre ammunition, to pervert the course of justice.

Judge Charteris rejected Strudwick's account that she was trying to protect her and her son when she told him to stash the package containing the bullets down the toilet s-bend.

Judge Charteris added that Strudwick acted out of "misguided loyalty" for her partner and should never have interfered in the police investigation.

Strudwick was sentenced to 20 months jail with a 10 month non-parole period.

After time already served, she will be eligible for parole in November.